Audio Codec

Altera_Forum · ‎02-21-2012

Hi ,

I have developed a embedded controller in VHDL to send I2C commands to the audio codec on DE2-115 board i.e WM8731.

When i send the programming data over I2C for it to send ADC data and i send it back into DAC . It works but everytime i program the FPGA , i hear clicking noise along with the sample audio from left or sometimes from right . And then i reset it again and i can still hear audio as if the device is shorted from inside and it is always transmitting ADC data ??:(,

I have taken a screen shot of audio data coming in from ADC and whats going into DAC , and this is when there is no audio input to ADC , and i can see some pulses there ??:confused:

Although on the DE2-115 schematic the mic line is grounded , there should not be any noise on this line .

Following are the data values i am sending over I2C :

constant R_Llinin_dat : std_logic_vector(8 downto 0):= "000011010";

constant R_Lheadfon_out_dat: std_logic_vector(8 downto 0):= "001111001";

constant Analgaudio_dat : std_logic_vector(8 downto 0):= "000010010"; -- Muting Mic

constant Digtlaudio_dat : std_logic_vector(8 downto 0):= "000000110";

constant PWR_dat : std_logic_vector(8 downto 0):= "000000000";

constant Digtlintf_dat : std_logic_vector(8 downto 0):= "000000001";

constant Samplng_dat : std_logic_vector(8 downto 0):= "000000010";

constant ActiveCtrl_dat : std_logic_vector(8 downto 0):= "000000001";

constant Rst_dat : std_logic_vector(8 downto 0):= "000000000";

Any clues ??

Altera_Forum · ‎02-27-2012

Has any one come across this problem , or you are all using Nios to control audio codec ???